I got an enermax Modu 82+ and I dung really care if it has the zero load bla bla cos unless the cpu is unlocked and overclocks well and gives significant advantage over i5 2500k then I wunt be bothering.

Surprised this has just come out now in all honesty. Most older psus 3-4 years will not be compatible so people on the older x58 and below ( the most likely upgraders in enthusaist market) will likely need a new psu if they want these power savings.

Its a cost that most will not have budgeted for as a decent 750-850 watt psu is easily £100 makes haswell not a very tempting upgrade unless its awesome.

Surely getting a decent platinum or gold rated psu would be a better energy saving if you're all that bothered? That way, there is better efficiency when you are actually using the rig, and then when you are not, turn it off at the socket....

It seems likely, however, that motherboard manufacturers will disable the new C6 and C7 states by default - circumventing the problem - rather than face support calls from angry customers wondering why their new motherboard and processor combination is failing to work on a known-good power supply.

What's the exact issue that would occur with an incompatible PSU and the C6/C7 states? Will it fail and cut power to the system, or just supply power inefficiently, churning through like 10-20W while supplying 2W to the system?

What's the exact issue that would occur with an incompatible PSU and the C6/C7 states? Will it fail and cut power to the system, or just supply power inefficiently, churning through like 10-20W while supplying 2W to the system?

While it's possible some PSUs would turn themselves off at low draw, the bigger problem is voltage ripple: without enough load on the rails, the PSU is likely to start flailing around and pumping too much voltage in one place and too little in another. Electronics don't like that very much, and while it's unlikely the ripple would be bad enough to break anything - the +12V rail isn't going to start giving 240V, for example - it would be enough to confuse the system and corrupt the contents of memory.

Basically, if you disable the C6/C7 sleep states you should be fine - but you'll be missing out on one of the new features brought about by Haswell. Like I say in the article, though, it's a bigger problem for battery-powered devices.

I guess using less power is a good thing, but having to buy a new PSU as well to take advantage of it! That's almost like Intel shooting themselves in the foot. I don't think I'll be upgrading to Haswell any time soon.

Annoying. I just bought a decent Corsair power supply. I have an 8-disk RAID10 in the same box; might that be enough of a buffer load, or are they concerned about the 3.3V line?

Its about the 12V2 exclusively used by the Cpu and nothing else, so no, other HW won't help you get over the minimum, according to here you may be fine with a Corsair Psu:

Quote:

However, the PSU selector on Intel's Reseller Center website includes a list of power supplies, and that list can be sorted by support for a minimum 12V2 load of 0 amps. I count only 23 units with that capability: 19 Corsair models, three InWin units, and a single Seasonic.

Not really seeing this as an issue as far as desktop PSUs go. While it would be a novel idea, especially the connected-sleep sort of deal, your average enthusiast isn't going to much care about the difference between .5W and 4W.

At least in the Windows world, my experience with sleeping a PC has never been all that great anyway. It's Windows - you either leave it running always and reboot when it starts getting flaky, or shut it down every night so it doesn't get flaky (and chew up your power bill, to boot.)

I'd be surprised if the major PSU OEMs and ODMs weren't already aware of the issue and will have it addressed by the time Haswell has actually dropped (for those that haven't already handled it, like Enermax.)

All in all, from what I've heard so far, Haswell is a bit less exciting than I'd expected, from a practical standpoint. From the engineering, super hardcore nerd point of view, it's exciting with the new arch and all. But it's definitely diminishing returns - if you aren't a bleeding-edger and you're at least on SB, doesn't seem worth the cash. I'll reserve judgment until benchmarks start coming out, but it seems less exciting than it did at first blush, all those months ago, at least in desktop-land.

All in all, from what I've heard so far, Haswell is a bit less exciting than I'd expected, from a practical standpoint. From the engineering, super hardcore nerd point of view, it's exciting with the new arch and all. But it's definitely diminishing returns - if you aren't a bleeding-edger and you're at least on SB, doesn't seem worth the cash. I'll reserve judgment until benchmarks start coming out, but it seems less exciting than it did at first blush, all those months ago, at least in desktop-land.

It's not meant to be exciting for desktops! It's meant to be exciting for mobile devices - tablets and laptops with Haswell chips will get better battery life, massively better iGPUs and other hardware-level features like Connected Standby which should allow Haswell devices to sleep like phones, saving power while staying connected. Intel are focusing almost exclusively on mobile because that's exactly where the money is!

We desktop enthusiasts (or even just desktop owners) are fading away nowadays - the vast majority of people don't need a desktop at all now. Heck, if I didn't game a lot or run stuff like folding/litecoin mining, my needs would be served almost completely by the 15 inch retina MBP.